ST. PETERSBURG, FLA. – One start doesn’t equal a fair evaluation for a pitcher making his first major league start, especially given the scenario in which right-hander Miguel Castro made his starting debut, but the 22-year-old’s performance definitely wasn’t as clean as the polished relief pitching that earned him rotation consideration.

Castro, whose emergence as a multiple-inning reliever surfaced a hidden gem, lasted just three batters into the fourth inning in the Orioles’ 4-3 loss to the Tampa Bay Rays, sending them to their 18th defeat in 22 games.

The Orioles (75-86) used their second-last game of the season to catch a glimpse of Castro (3-3) in a starting role. He allowed seven base runners and twice stranded two runners on before allowing a three-run homer to Brad Miller in the fourth that essentially ended his night.

“[He was] OK, he got a little tired,” Orioles manager Buck Showalter said of Castro. “I’m not sure. He worked through a lot of trouble. It wasn’t like it was an unscathed first three innings. It was a good step for him. We’ll see if he can build on it, give us some options as he goes forward.”

Whether Castro will have a chance to earn a rotation spot come spring remains to be seen, but his first start did expose some of his weaknesses, including a slow time to the plate that hurt him holding runners and an untimely wild pitch in the Rays’ three-run fourth.

“Different look,” Showalter said. “Different presentation. You watch him during the course of a day preparing for a start. There wasn’t a whole lot of change in him. He’s a pretty under-control guy. He likes to compete. He’s a smart guy. He knows what’s going on and we certainly don’t draw a lot of attention to it for him. It’s little things like times to the plate. He fluctuates all over the place. It’s something that he’s got to do a better job with before they get here. This is a tough place to be teaching people to be perfect to the plate. That stuff’s got to start in [Short-A] Aberdeen.”

With the defeat, the Orioles will end the season having lost their last five road series, and 12 of their last 14 games away from Camden Yards overall. They are just 2-8-1 in road series since the All-Star break.

Castro needed just 11 pitches to get through the first inning, but then dodged damage in the second and third innings. He put two runners in scoring position with one out in the second inning on Corey Dickerson’s single and Adeiny Hechavarria’s double, but Orioles first baseman Chris Davis cut down Dickerson at home on a grounder by Miller to erase the lead runner. Castro struck out Daniel Robertson to escape the inning.

In the third, a leadoff single by Mallex Smith, a fielder’s choice by Kevin Kiermaier and a one-out walk to Lucas Duda put two on. Kiermaier stole third to put runners at the corners, but Castro struck out Wilson Ramos and induced an inning-ending flyout off the bat of Logan Morrison.

Castro then allowed back-to-back singles to Dickerson and Hechavarria to open the fourth, and both runners moved into scoring position on a wild pitch before Miller put a 2-2 slider deep into the right-field stands.

Miller entered the night hitting just .198 on the season and had just one homer over his previous 22 games.

“I was trying to locate the ball low in the zone throughout the whole game,” Castro said through translator Ramón Alarcón. “Obviously there was one pitch which he took advantage of it. After that, I just tried to compete again.”

Castro, who posted a 2.38 ERA in his first 32 relief appearances this season spanning 53 innings, ended the season allowing 12 earned runs in 131/3 innings over his final seven games.

Orioles offense rallies late: The Orioles rallied late, bringing the go-ahead run to the plate in the ninth after being held scoreless through the first seven innings.

Trailing 4-2 in the ninth, the Orioles put runners at the corners with no outs against Rays closer Alex Colomé after J.J. Hardy’s second double of the night led off the inning, followed by Chance Sisco’s single.

Pinch hitter Seth Smith struck out, Anthony Santander’s sac fly to center scored Hardy to make it 4-3 and Jonathan Schoop’s sinking line drive to center was caught by Kiermaier to end the game.

“Whenever we get something rolling, it’s a good sign, especially off the caliber of pitcher that Colomé is,” Sisco said. “Just trying to put good at-bats together and try to string something together.”

Ending the drought:Pedro Álvarez’s two-run single in the eighth, which came off former Orioles reliever Tommy Hunter, scored the visitors’ first runs in 23 innings. The Orioles hadn’t scored a run since putting up three in the second inning of Wednesday’s 5-3 loss at the Pittsburgh Pirates.

Rays right-hander Chris Archer tossed five scoreless innings, allowing just two hits and striking out six, including striking out the side in the second inning. The Orioles’ only extra-base hit off him came in the second inning on Hardy’s double.

The Orioles brought the tying run to the on-deck circle with one out in the eighth after Álvarez’s hit, but Chris Davis ended the inning by bouncing into a 4-5-3 double play.

“I think it was as much that they were making some mistakes and we were doing something with them,” Showalter said. “Archer’s got what, 200 innings? One of the best pitchers in the league, and we didn’t do a whole lot off him to create very many opportunities.”

Rays test Sisco: The Rays stole four bases against Sisco, who was making his fourth major league start.

“We can do a little better job throwing, in throwing them out, but Chance did a good job,” Showalter said. “He threw the guy out at third. We just didn’t make the play. Those are the little things that get magnified [in a first start] somewhat when you’re starting because you’re seeing a lot more hitters and guys have a better feel for you.”

Sisco is 0-for-5 throwing out base runners.

“I feel really comfortable back there,” Sisco said. “Just trying to put a good throw down there to second or third base, wherever they’re trying to run, and give us the best shot to throw them out.”

Hitting streak ends:Orioles left fielder Trey Mancini had his hitting streak end at 17 after he went 0-for-2 with two walks Saturday.

Mancini’s streak was the longest by a rookie in Orioles history.

eencina@baltsun.com

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